PubMed Health⌕ Search

Biomedical subjects

Ron Waksman

Publications and source records attributed to Ron Waksman.

At least 19 recordsLinked to original sources
PubMed2004

Usefulness of periprocedural creatinine phosphokinase-MB release to predict adverse outcomes after intracoronary radiation therapy for in-stent restenosis.

We aimed to analyze periprocedural creatinine phosphokinase (CPK)-MB elevation in patients treated with intracoronary radiation therapy (IRT) for in-stent restenosis (ISR) to risk stratify these patients. The clinical significance of periprocedural CPK-MB elevation after IRT for ISR is unknown. An elevated CPK-MB has been associated with increased mortality after conventional angioplasty. We evaluated 1,326 patients who were enrolled in radiation trials for ISR at the Washington Hospital Center using gamma- and beta-emitters. Patients were analyzed according to degree of CPK-MB increase within 24 hours of the index IRT procedure (normal CPK-MB, CPK-MB 1 to 3 times the upper limit of normal, or CPK-MB >3 times the upper limit of normal). Patients with CPK-MB >3 times the upper limit of normal were older (64 +/- 12 years, p = 0.04), more likely to be smokers (64%, p = 0.04), hypertensive (85%, p <0.01), and diabetic (49%, p = 0.04). The cohort with the highest CPK-MB release (CPK-MB >3 times the upper limit of normal) had significantly higher rates of adverse clinical events at 12 months (major adverse cardiac events 40%, p <0.01), including death (9.3%, p <0.01) and late thrombosis (6.3%, p <0.01). Periprocedural CPK-MB elevation is of prognostic importance in patients treated with IRT for ISR, and its analysis appears to be mandatory to risk stratify these patients. The impact of glycoprotein IIb/IIIa antagonists in reducing periprocedural CPK-MB release awaits evaluation.

Aged↗
PubMed2004

Five-year follow-up after intracoronary gamma radiation therapy for in-stent restenosis.

BACKGROUND: The Washington Radiation for In-Stent Restenosis Trial is a double-blinded randomized study evaluating the effects of intracoronary radiation therapy (IRT) in patients with in-stent restenosis (ISR). METHODS AND RESULTS: One hundred thirty patients with ISR (100 native coronary and 30 vein grafts) underwent percutaneous transluminal coronary angioplasty, laser ablation, rotational atherectomy, or additional stenting (36% of lesions). Patients were randomized to either 192-Iridium IRT or placebo, with a prescribed dose of 15 Gy to a 2-mm radial distance from the center of the source. Angiographic restenosis (27% versus 56%, P=0.002) and target vessel revascularization (26% versus 68%, P<0.001) were reduced at 6 months in patients treated with IRT. Between 6 and 60 months, patients treated with IRT compared with placebo had more target lesion revascularization (IRT, 21.6% versus placebo, 4.7%; P=0.04) and target vessel revascularization (IRT, 21.5% versus placebo, 6.1%; P=0.03). At 5 years, the major adverse cardiac event rate was significantly reduced with IRT (46.2% versus 69.2%, P=0.008). CONCLUSIONS: In the Washington Radiation for In-Stent Restenosis Trial, patients with ISR treated with IRT using 192-Iridium had a reduction in the need for repeat target lesion and vessel revascularization at 6 months and 5 years.

Cardiac Catheterization↗
PubMed2003

Comparison of the angiographic outcomes after beta versus gamma vascular brachytherapy for treatment of in-stent restenosis.

This study was designed to compare the angiographic outcomes of beta versus gamma vascular brachytherapy (VBT). We reviewed the angiographic results of 636 lesions (212 that underwent beta and 212 that underwent gamma VBT, and 212 that received placebo) with native coronary in-stent restenosis matched for lesion length, vessel size, preprocedure minimum lumen diameter (MLD), and time to angiographic follow-up in the various randomized clinical trials and studies. Baseline lesion complexity was similar in these 3 groups. Final MLD was smaller in the beta VBT group than in the gamma VBT or placebo group. At follow-up, beta and gamma VBT significantly reduced both angiographic restenosis (34.4% for beta VBT, 26.4% for gamma VBT, and 50.9% in the placebo group; p <0.0001) and recurrent lesion length (9.2 mm for beta VBT, 8.4 mm for gamma VBT, and 15.5 mm placebo, p <0.0001) compared with placebo. Gamma VBT was associated with a greater reduction in restenosis outside the stent than beta VBT. By multivariable analysis, independent angiographic predictors of treated segment restenosis included beta or gamma VBT, lesion length, and vessel size. In matched lesions, beta and gamma VBT achieved similar reductions in treated segment restenosis and recurrent lesion length compared with placebo.

Adult↗
PubMed2003

Comparison of effectiveness and safety of three different antithrombotic regimens (bivalirudin, eptifibatide, and heparin) in preventing myocardial ischemia during percutaneous coronary intervention.

The aim of this retrospective, observational analysis was to compare the efficacy and safety of 3 antithrombotic regimens: bivalirudin, eptifibatide plus heparin, and heparin alone, with emphasis on preventing interventional procedural creatinine kinase-MB fraction (CK-MB) release, and consequently, myocardial necrosis.

Aged↗
PubMed2003

Comparison of creatine kinase elevation and outcome of comparison of percutaneous coronary intervention for saphenous vein graft in-stent restenosis versus de novo stenosis.

Percutaneous coronary intervention of saphenous vein grafts is associated with distal embolization. We aimed to compare potential differences in patients undergoing percutaneous coronary intervention for in-stent restenosis with de novo saphenous vein graft lesions. Myocardial necrosis was associated with higher mortality regardless of lesion type.

Age Factors↗
PubMed2003

Volumetric intravascular ultrasound evidence that distal embolization during acute infarct intervention contributes to inadequate myocardial perfusion grade.

We studied 35 consecutive patients with myocardial infarction (MI) who were treated with direct infarct percutaneous coronary intervention (PCI) using standard angiographic (complete assessment of flow grade and blush grade) and pre- and post-PCI volumetric intravascular ultrasound analysis. Plaque reduction, which is evidence of distal embolization, contributes to inadequate tissue reperfusion in this lesion setting and supports the use of distal protection in the setting of an acute MI.

Aged↗
PubMed2003

Repeat intracoronary radiation for recurrent in-stent restenosis in patients who failed intracoronary radiation.

BACKGROUND: Intracoronary radiation therapy (IRT) is the only proven treatment for in-stent restenosis (ISR). It is, however, associated with a significant failure rate. The present study evaluated the outcomes of patients who underwent repeat intracoronary radiation for recurrent ISR. METHODS AND RESULTS: Fifty-one consecutive patients who failed a previous radiation treatment, presented with angina and angiographic evidence of ISR, and were treated with percutaneous coronary intervention (PCI) and repeat radiation to the same segment were studied. Twenty-five patients were treated with gamma radiation in a dose of 15 Gy, and 26 were treated with beta radiation doses of 18.3 to 23 Gy. The mean cumulative dose for this cohort was 39.5+/-11.9 Gy (range, 29 to 75.6 Gy). The outcomes of those patients were compared with outcomes of 299 patients who also failed initial radiation but were treated with repeat conventional PCI to a previously irradiated segment without repeat radiation. At 9 months after treatment, the repeat-IRT group had lower rates of target lesion revascularization (23.5% versus 54.6%; P<0.001) and major adverse cardiac events, including target vessel revascularization (29.4% versus 61.3%; P<0.001). At 9 months, patients with repeat IRT were free of angiographic and clinical events related to the radiation therapy. CONCLUSIONS: Repeat gamma or beta radiation to treat failed IRT for ISR after conventional PCI is safe and effective at 9 months and should be considered as a therapeutic option for this difficult patient subset.

Angina Pectoris↗
PubMed2003

Predictors of subacute stent thrombosis: results of a systematic intravascular ultrasound study.

BACKGROUND: Factors leading to subacute stent thrombosis after percutaneous coronary intervention (PCI) have not been well established. We assessed the pre- and post-PCI intravascular ultrasound (IVUS) characteristics of subacute stent thrombosis. METHODS AND RESULTS: We analyzed 7484 consecutive patients without acute myocardial infarction who were treated with PCI and stenting and underwent IVUS imaging during the intervention. Twenty-seven (0.4%) had angiographically documented subacute closure <1 week after PCI (median time to subacute closure, 24 hours). Subacute closure lesions were compared with a control group (selected to be 3 times the abrupt closer group) matched by procedure date (within 6 months), age, gender, stable or unstable angina, lesion location, and additional treatment (balloon angioplasty or atherectomy). Postintervention IVUS did not identify a cause in 22% and did identify at least 1 cause for abrupt closure in 78% of patients (versus 33% in matched lesions, P=0.0002). In 48% of the patients, there were multiple causes in 48% (versus 3% in matched lesions, P<0.0001). Causes included dissection (17%), thrombus (4%), and tissue protrusion within the stent struts leading to lumen compromise lumen (4%). A total of 83% of patients with >1 of these abnormal morphologies also had reduced lumen dimensions post-PCI (final lumen <80% reference lumen). Preprocedural lesion characteristics were not different from matched lesions. CONCLUSIONS: Subacute stent thrombosis is infrequently related to the preintervention lesion characteristics. Inadequate postprocedure lumen dimensions, alone or in combination with other procedurally related abnormal lesion morphologies (dissection, thrombus, or tissue prolapse), contribute to this phenomenon.

Angioplasty, Balloon, Coronary↗
PubMed2003

Intravascular ultrasound analysis of infarct-related and non-infarct-related arteries in patients who presented with an acute myocardial infarction.

BACKGROUND: Previous studies have reported diffuse destabilization of atherosclerotic plaques in acute myocardial infarction (AMI). METHODS AND RESULTS: We used intravascular ultrasound (IVUS) to assess 78 coronary arteries (38 infarct-related arteries [IRAs] with culprit and nonculprit lesions and 40 non-IRAs) from 38 consecutive AMI patients. IVUS analysis included qualitative and quantitative measurements of reference and lesion external elastic membrane (EEM), lumen, and plaque plus media (P&M) area. Positive remodeling was defined as lesion/mean reference EEM >1.0. Culprit lesions were identified by a combination of ECG, wall motion abnormalities (ventriculogram or echocardiogram), scintigraphic perfusion defects, and coronary angiogram. Culprit lesions contained more thrombus (23.7% versus 3.4% in nonculprit IRA plaques and 3.1% in non-IRA plaques; P=0.0011). Culprit lesions were predominantly hypoechoic (63.2% versus 37.9% of nonculprit IRA plaques and 28.1% of non-IRA plaques; P=0.0022). Culprit lesions were longer (17.5+/-10.1, 9.8+/-4.0, and 10.3+/-5.7 mm, respectively; P<0.0001), had larger EEM area (15.0+/-6.0, 11.5+/-5.7, and 12.6+/-5.6 mm2, respectively; P=0.0353) and P&M area (13.0+/-6.0, 7.5+/-3.7, 9.3+/-4.3 mm2, respectively; P<0.0001), smaller lumens (2.0+/-0.9, 4.1+/-3.1, and 3.4+/-2.5 mm2, respectively; P=0.0009), and more positive remodeling (79.4%, 59.0%, and 50.8%, respectively; P=0.0155). The frequency of plaque rupture/dissection was greater in culprit, nonculprit IRA, and non-IRA plaques in AMI patients than in a control group of chronic stable angina patients with multivessel IVUS imaging. CONCLUSIONS: Culprit plaques have more markers of instability (thrombus, positive remodeling, and large plaque mass); however, these markers of instability are not typically found elsewhere. This suggests that the vascular event in AMI patients is determined by local pre-event lesion morphologies.

Angina Pectoris↗
PubMed2003

Intravascular brachytherapy for native coronary ostial in-stent restenotic lesions.

OBJECTIVES: We analyzed the effects of vascular brachytherapy (VBT) on ostial in-stent restenosis (ISR). BACKGROUND: In-stent restenosis has a high recurrence rate after percutaneous reintervention. The recurrence rate of ostial ISR lesions and the impact of VBT remain unknown. METHODS: We evaluated 133 patients with native coronary ostial ISR from a pooled database of 990 patients enrolled in randomized VBT trials. Independent quantitative angiography was performed at baseline and follow-up in 45 gamma, 27 beta, and 61 placebo patients. RESULTS: Binary restenosis was significantly higher in placebo than radiated patients (75.4% vs. 17.8% in gamma vs. 22.2% in beta, p < 0.0001). The treatment effect of both gamma (odds ratio [OR] 0.06; 95% confidence interval [CI] 0.02 to 0.17) and beta VBT (OR 0.10; 95% CI 0.03 to 0.31) was maintained after controlling for differences in baseline lesion length. Proximal and distal radiation edge restenosis rates were similar among the groups. Vascular brachytherapy of true aorto-ostial lesions (n = 34) was similarly beneficial: restenosis rates of placebo versus gamma or beta patients of 83.3% versus 6.7% versus 28.6%, p = 0.0002. CONCLUSIONS: Conventional treatment of ostial ISR is associated with a recurrence rate of over 75%. Vascular brachytherapy with either gamma or beta sources results in significant and similar reductions in restenosis compared with placebo. Similar benefits after VBT prevail in true aorto-ostial lesions.

Aorta↗
PubMed2003

Catheter-based autologous bone marrow myocardial injection in no-option patients with advanced coronary artery disease: a feasibility study.

OBJECTIVES: We conducted a pilot study to evaluate the feasibility of transendocardial delivery of autologous bone marrow (ABM) strategy in patients with severe symptomatic chronic myocardial ischemia not amenable to conventional revascularization. BACKGROUND: Transendocardial injection of ABM cells appears to enhance perfusion of ischemic porcine myocardium. METHODS: Ten patients underwent transendocardial injection of freshly aspirated and filtered unfractionated ABM using left ventricular electromechanical guidance. Twelve injections of 0.2 ml each were successfully delivered into ischemic noninfarcted myocardium pre-identified by single-photon emission computed tomography perfusion imaging. RESULTS: Autologous bone marrow injection was successful in all patients and was associated with no serious adverse effects; in particular, there was no arrhythmia, evidence of infection, myocardial inflammation, or increased scar formation. Two patients were readmitted for recurrent chest pain. At three months, Canadian Cardiovascular Society angina score significantly improved (3.1 +/- 0.3 vs. 2.0 +/- 0.94, p = 0.001), as well as stress-induced ischemia occurring within the injected territories (2.1 +/- 0.8 vs. 1.6 +/- 0.8, p < 0.001). Treadmill exercise duration, available in nine patients, increased, but the change was not significant (391 +/- 155 vs. 485 +/- 198, p = 0.11). CONCLUSIONS: This study provides preliminary clinical data indicating feasibility of catheter-based transendocardial delivery of ABM to ischemic myocardium.

Bone Marrow Transplantation↗